High oxidative stability of a complex fish liver oil nano-capsules in response to long-term storage, and to hyperthermal and sunlight exposure.

BACKGROUND: In this study, a biocompatible nano-carrying platform using chitosan (ChI) and chondroitin sulfate (ChS) was developed for the encapsulation of cobia liver oil (CBLO) to prevent its oxidation and improve its absorption. An ionic gelation method was applied to encapsulate CBLO with different weight ratios (from 1.0 to 1.5) to obtain ChS-ChI nano-capsules (ChS-ChI@CBLO NCs). RESULTS: Morphological observations of the nano-capsules revealed a spherical shape and diameter around 267-381 nm. The maximum loading capacity (LC) and encapsulation efficiency (EE) for ChS-ChI@CBLO NCs estimated by thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) analysis were 25.7% and 56.2%, respectively. The structural stability of ChS-ChI@CBLO NCs was confirmed through differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis; moreover DSC also further confirmed the oxidative stability of ChS-ChI@CBLO NCs. Fourier-transform infrared (FTIR) spectra confirmed the excellent stability of ChS-ChI@CBLO NCs against high temperature and sunlight exposure. Biocompatibility analysis also verified the non-toxicity of ChS-ChI@CBLO NCs, further indicating safety and potential application in complex-nutritional supplements. CONCLUSION: Nano-degree of ChS-ChI@CBLO NCs has a loading capacity and encapsulation efficiency of around 16.5 ~ 25.7% and 33.4 ~ 56.2%, respectively, for encapsulation of CBLO. Characterization results also indicate that ChS-ChI@CBLO NCs display high oxidative stability against long-term, hyperthermal, and sunlight exposure. Bioassay results confirm that the ChS-ChI@CBLO NCs are safe and non-toxic. This study demonstrates that nano-capsules are also beneficial in preventing sensitive compounds from metamorphosis, and are non-toxic. These materials are suitable for use in the food and pharmaceutical industries. © 2023 Society of Chemical Industry.

An Efficient Grid-Based Geocasting Scheme for Wireless Sensor Networks.

In a wireless sensor network (WSN), geocasting is a location-based routing protocol used for data collection or information delivery. In geocasting, a target region usually contains many sensor nodes with limited battery capacity, and sensor nodes in multiple target regions need to transmit data to the sink. Therefore, how to use location information to construct an energy efficient geocasting path is a very important issue. FERMA is a geocasting scheme for WSNs based on Fermat points. In this paper, an efficient grid-based geocasting scheme for WSNs, which is called GB-FERMA, is proposed. The scheme uses the Fermat point theorem to search for the specific nodes as Fermat points in a grid-based WSN, and it selects the optimal relay nodes (gateways) in the grid structure to realize energy-aware forwarding. In the simulations, when the initial power 0.25 J, the average energy consumption of GB-FERMA is about 53% of FERMA-QL, 37% of FERMA, and 23% of GEAR; however, when with the initial power 0.5 J, the average energy consumption of GB-FERMA is about 77% of FERMA-QL, 65% of FERMA, and 43% of GEAR. The proposed GB-FERMA can effectively reduce the energy consumption and thus prolong the lifetime of the WSN.

Green extraction and purification of chondroitin sulfate from jumbo squid cartilage by a novel procedure combined with enzyme, ultrasound and hollow fiber dialysis.

Chondroitin sulfate (ChS) from marine sources is gaining attention. The purpose of this study was to extract ChS from jumbo squid cartilage (Dosidicus gigas) using ultrasound-assisted enzymatic extraction (UAEE). An ultrasound with protease assistance, including either alcalase, papain or Protin NY100 was used to extract ChS. The results showed that alcalase had the best extraction efficiency. The response surface methodology was employed to evaluate the relationship between extraction conditions and extraction yield of ChS. The ridge max analysis revealed a maximum extraction yield of 11.9 mg ml- 1 with an extraction temperature of 59.40 °C, an extraction time of 24.01 min, a pH of 8.25, and an alcalase concentration of 3.60%. Compared to ethanol precipitation, purification using a hollow fiber dialyzer (HFD) had a higher extraction yield of 62.72% and purity of 85.96%. The structure characteristics of ChS were identified using FTIR, 1 H-NMR, and 13 C-NMR to confirm that the purified ChS structure was present in the form of chondroitin-4-sulfate and chondroitin-6-sulfate. The results of this study provide a green and efficient process for extraction and purification of ChS and are essential for the use of ChS for the development and production of nutrient food products or pharmaceuticals. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05701-7.

Chitosan-Based Anti-Oxidation Delivery Nano-Platform: Applications in the Encapsulation of DHA-Enriched Fish Oil.

Refined cobia liver oil is a nutritional supplement (CBLO) that is rich in polyunsaturated fatty acids (PUFAs), such as DHA and EPA; however, PUFAs are prone to oxidation. In this study, the fabrication of chitosan-TPP-encapsulated CBLO nanoparticles (CS@CBLO NPs) was achieved by a two-step method, including emulsification and the ionic gelation of chitosan with sodium tripolyphosphate (TPP). The obtained nanoparticles were inspected by dynamic light scattering (DLS) and showed a positively charged surface with a z-average diameter of between 174 and 456 nm. Thermogravimetric analysis (TGA) results showed the three-stage weight loss trends contributing to the water evaporation, chitosan decomposition, and CBLO decomposition. The loading capacity (LC) and encapsulation efficiency (EE) of the CBLO loading in CS@CBLO NPs were 17.77-33.43% and 25.93-50.27%, respectively. The successful encapsulation of CBLO in CS@CBLO NPs was also confirmed by the Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. The oxidative stability of CBLO and CS@CBLO NPs was monitored by FTIR. As compared to CBLO, CS@CBLO NPs showed less oxidation with a lower generation of hydroperoxides and secondary oxidation products after four weeks of storage. CS@CBLO NPs are composed of two ingredients that are beneficial for health, chitosan and fish oil in a nano powdered fish oil form, with an excellent oxidative stability that will enhance its usage in the functional food and pharmaceutical industries.

Dual Stimuli-Responsive Block Copolymers with Adjacent Redox- and Photo-Cleavable Linkages for Smart Drug Delivery.

A novel dual-stimuli cleavable linker containing adjacent UV light-sensitive o-nitrobenzyl ester and GSH-responsive disulfide bonds was first designed and synthesized to increase the responsivity to external stimuli. The functionalized linker was then utilized to prepare a dual-responsive amphiphilic block copolymer using ring-opening polymerization and atom transfer radical polymerization. The copolymer formed a micelle in an aqueous solution and showed dual-stimuli responses including photo-mediated cleavage under UV light irradiation at 365 nm as well as reduction-responsive degradation in the presence of a reducing agent. The micelle was nontoxic against three cell lines and majorly internalized via clathrin-mediated endocytosis. Doxorubicin (Dox) was loaded in the hydrophobic core of the micelle. Enhancement of a cell-killing effect against A549 cells was clearly observed in the Dox-encapsulated micelle when exposed to UV light.

Cooperative Sensing Data Collection and Distribution with Packet Collision Avoidance in Mobile Long-Thin Networks.

Mobile ad hoc networks (MANETs) have gained a lot of interests in research communities for the infrastructure-less self-organizing nature. A MANET with fleet cyclists using smartphones forms a two-tier mobile long-thin network (MLTN) along a common cycling route, where the high-tier network is composed of 3G/LTE interfaces and the low-tier network is composed of IEEE 802.11 interfaces. The low-tier network may consist of several path-like networks. This work investigates cooperative sensing data collection and distribution with packet collision avoidance in a two-tier MLTN. As numbers of cyclists upload their sensing data and download global fleet information frequently, serious bandwidth and latency problems may result if all members rely on their high-tier interfaces. We designed and analyzed a cooperative framework consisting of a distributed grouping mechanism, a group merging and splitting method, and a sensing data aggregation scheme. Through cooperation between the two tiers, the proposed framework outperforms existing works by significantly reducing the 3G/LTE data transmission and the number of 3G/LTE connections.

Intelligent attendance monitoring system with spatio-temporal human action recognition.

This paper proposes an intelligent attendance monitoring system based on spatio-temporal human action recognition, which includes human skeleton gait recognition, multi-action body silhouette recognition and face recognition. Our system solves several problems, for example, when a mask is worn to conceal the face, which leads to a decrease in recognition accuracy performance, and when a 3D face mask is used to fake an identity. The skeleton gait feature of our intelligent attendance monitoring system uses a temporal weighted K-nearest neighbours algorithm to train the recognition model and carry out identification, while the multi-action body silhouette feature uses a multiple K-nearest neighbours algorithm to train the recognition model, identify the person and vote on the outcome. Using the proposed system, which integrates skeleton gait features, action silhouette features and face features, more effective recognition can be achieved. When the system encounters a situation with feature masking, such as when an individual is wearing a mask or has changed their clothes, or when the viewing angle is masked, it can continue to deliver good recognition ability through multi-angle skeleton synthesis gait recognition. Our experimental results show that the recognition accuracy of the system is 83.33% when a specific person wears a mask and passes through a monitored area. The intelligent attendance monitoring system uses a LINE messaging API as the access control notification function and provides a responsive web platform that allows managers to perform follow-up management and monitoring.

The Impact of Oxygen Pulse and Its Curve Patterns on Male Patients with Heart Failure, Chronic Obstructive Pulmonary Disease, and Healthy Controls-Ejection Fractions, Related Factors and Outcomes.

Oxygen pulse (O2P) is a function of stroke volume and cellular oxygen extraction and O2P curve pattern (O2PCP) can provide continuous measurements of O2P. However, measurements of these two components are difficult during incremental maximum exercise. As cardiac function is evaluated using ejection fraction (EF) according to the guidelines and EF can be obtained using first-pass radionuclide ventriculography, the aim of this study was to investigate associations of O2P%predicted and O2PCP with EF in patients with heart failure with reduced or mildly reduced ejection fraction (HFrEF/HFmrEF) and chronic obstructive pulmonary disease (COPD), and also in normal controls. This was a prospective observational cross-sectional study. Correlations of resting left ventricular EF, dynamic right and left ventricular EFs and outcomes with O2P% and O2PCP across the three participant groups were analyzed. A total of 237 male subjects were screened and 90 were enrolled (27 with HFrEF/HFmrEF, 30 with COPD and 33 normal controls). O2P% and the proportions of the three types of O2PCP were similar across the three groups. O2P% reflected dynamic right and left ventricular EFs in the control and HFrEF/HFmrEF groups, but did not reflect resting left ventricular EF in all participants. O2PCP did not reflect resting or dynamic ventricular EFs in any of the subjects. A decrease in O2PCP was significantly related to nonfatal cardiac events in the HFrEF/HFmrEF group (log rank test, p = 0.01), whereas O2P% and O2PCP did not predict severe acute exacerbations of COPD. The findings of this study may clarify the utility of O2P and O2PCP, and may contribute to the currently used interpretation algorithm and the strategy for managing patients, especially those with HFrEF/HFmrEF. (Trial registration number NCT05189301.).

Comparative study of an antimicrobial peptide and a neuropeptide conjugated with gold nanorods for the targeted photothermal killing of bacteria.

There are certain disadvantages in treating bacterial infections through conventional methods. For this reason, the current study does focus on combating bacterial wound infections by photothermal therapy assisted by gold nanorod-peptide conjugates (GNR-peptide conjugates). Two peptides, the cationic antimicrobial peptide LL-37 and neuropeptide ANGIOPEP-2 both with specificity for targeted bacterial binding, were conjugated with GNR surface through electrostatic interactions. The GNR-peptide conjugates showed good biocompatibility, sufficient stability, enhanced targeting, potential photothermal killing of bacteria, and possible acceleration of wound healing. The photo-biomodulation properties of NIR improved the wound closure rates through enhanced cell migration. The multifunctional LL37-conjugated GNRs significantly enhanced photothermal therapeutic outcomes based on bacterial targeting with promising wound healing properties.

Ultrasonic-Assisted Extraction and Structural Characterization of Chondroitin Sulfate Derived from Jumbo Squid Cartilage.

Chondroitin sulfate (ChS) is usually used as an oral nutraceutical supplement, and has been popular in Asia, Europe, and United States for many years. In this study, a potential and sustainable source of ChS from jumbo squid (Dosidicus gigas) cartilage was explored; ultrasound-assisted extraction (UAE) was used to extract ChS from jumbo squid cartilage. The result of mass transfer coefficients based on Fick's law showed that UAE had higher mass transfer efficacy. The response surface methodology (RSM) combined with Box-Behnken design (BBD) was employed to evaluate the effects of the extraction parameters. The optimal conditions were extraction temperature of 52 °C, extraction time of 46 min, and NaOH concentration of 4.15%. The crude extract was precipitated by 50% ethanol, which obtained a purified ChS with 23.7% yield and 82.3% purity. The purified ChS measured by energy-dispersive X-ray spectroscopy (EDX) had a carbon to sulfur molar ratio of approximately 14:1. The FTIR, 1H, and 13C NMR confirmed jumbo squid ChS were present in the form of chondroitin-4-sulfate and chondroitin-6-sulfate, with a 4S/6S ratio of 1.62. The results of this study provide an efficient process for production and purification of ChS, and are significant for the development and utilization of ChS from jumbo squid cartilage in the nutrient food or pharmaceutical industries.

Near-Infrared Light-Triggered Drug Release from Ultraviolet- and Redox-Responsive Polymersome Encapsulated with Core-Shell Upconversion Nanoparticles for Cancer Therapy.

Combining upconversion nanoparticles (UCNPs) and UV-sensitive polymers to form a smart drug delivery system (DDS) is a promising strategy to circumvent drawbacks of direct UV excitation in clinical applications. This study tuned up core-shell UCNPs with a shell thickness of 6 nm and emission wavelength falling in the ultraviolet region at 350 nm under near-infrared (NIR) light irradiation at 980 nm. An amphiphilic block copolymer with UV-responsive o-nitrobenzyl ester (ONB) next to a glutathione (GSH)-responsive disulfide linkage was synthesized and formulated into a polymersome. Core-shell UCNPs and doxorubicin (DOX) were simultaneously encapsulated into the polymersome during double emulsion for DDS. The combination of NIR light-inducing photolysis of the ONB linkage and GSH cleaving the disulfide linkage enhanced DOX release for chemotherapy. From in vitro evaluation, the polymersome alone was nontoxic against three lung cancer cell lines, but the one loaded with core-shell UCNPs and DOX showed severe cell-killing effect under the assistance of a 980 nm diode laser. In vivo study in A549 tumor-bearing mice verified significant inhibition of tumor growth in mice treated with the polymersome containing core-shell UCNPs and DOX under 980 nm diode laser irradiation as compared with those without laser irradiation and those treated with free DOX. This intriguing nanomedicine of well-defined structures responsive to NIR light and reducing agents offers potential for smart DDS applications.

Multi-Stimuli-Responsive DOX Released from Magnetosome for Tumor Synergistic Theranostics.

BACKGROUND: To improve responses to tumor microenvironments for achieving a better therapeutic outcome in combination cancer therapy, poly(ε-caprolactone)-SS-poly(methacrylic acid) diblock copolymer (PCL-SS-PMAA) with a disulfide linkage between the hydrophobic and hydrophilic junctions was synthesized. MATERIALS AND METHODS: Repeating units of PCL and PMAA in PCL-SS-PMAA were controlled and formulated into polymersomes (PSPps). Truncated octahedral Fe3O4 nanoparticles (IONPs) were synthesized and encapsulated to produce IONPs-PSPps NPs and doxorubicin (DOX) was further loaded to produce IONPs-PSPps@DOX NPs for theranostic applications. RESULTS: IONPs-PSPps NPs remained a superparamagnetic property with a saturation magnetization value of 85 emu⋅gFe3O4 -1 and a relaxivity value of 180 mM-1⋅s-1. Upon exposure to an alternating magnetic field (AMF), IONPs-PSPps NPs increased temperature from 25°C to 54°C within 15 min. Among test groups, the cell apoptosis was greatest in the group exposed to IONPs-PSPps@DOX NPs with AMF and magnet assistance. In vivo T2-weighted magnetic resonance images of A549 tumor-bearing mice also showed highest contrast and greatest tumor suppression in the tumor with AMF and magnet assistance. CONCLUSION: IONPs-PSPps@DOX NPs are a potential theranostic agent having multifaceted applications involving magnetic targeting, MRI diagnosis, hyperthermia and chemotherapy.

Tuning the Distance of Rattle-Shaped IONP@Shell-in-Shell Nanoparticles for Magnetically-Targeted Photothermal Therapy in the Second Near-Infrared Window.

Construction of multifunctional nanoparticles (NPs) with near-infrared (NIR) plasmonic responses is considered a versatile and multifaceted platform for several biomedical applications. Herein, a double layer of Au/Ag alloy on the surface of truncated octahedral iron oxide NPs (IONPs) was prepared and the distance between the layers was controlled to exhibit broad and strong NIR absorption. The rattle-shaped IONP@shell-in-shell nanostructure showed light-response to the NIR biological window from 650 to 1300 nm for photothermal therapy (PTT) and magnetic guidance for hyperthermia and magnetic resonance imaging (MRI) diagnosis. Exposing the aqueous solution of IONP@shell-in-shell to a 1064 nm diode laser, its heat conversion efficiency was ∼28.3%. The in vitro cell viability at a gold concentration of 100 ppm was ∼85%, and decreased to ∼16% when the cells were treated with the NIR irradiation and magnetic attraction. T2-weighted MRI images showed a clear accumulation of IONP@shell-in-shell at the tumor site with magnetic attraction. In vivo luminescence tumor images explained that the IONP@shell-in-shell could reduce the U87MG-luc2 cancer cell proliferation in mice with the NIR irradiation and magnetic attraction. These results indicate the IONP@shell-in-shell as a promising nanomedicine for PTT, magnetic targeting, and magnetic resonance imaging (MRI).

Escape from the destruction of the galvanic replacement reaction for solid → hollow → solid conversion process in one pot reaction.

Based on the difference in the redox potentials between two metal species, the galvanic replacement reaction is known to create an irreversible process to generate hollow nanostructures in a wide range of shapes. In the context of galvanic replacement reaction, continuing etching leads to the general collapse of the hollow structures because of the excess amount of oxidizing agent. We demonstrate the growth of solid nanostructures from a hollow frame-like architecture in the course of a galvanic replacement reaction without any morphology destruction. We report the successful composition transformation of solid Ag with a wide range of shapes, such as plate, decahedron, rod, prism, sphere, and foil, from as thin as <10 nm up to 5 µm and with an area of ∼4 mm(2), to their solid Au counterparts using straightforward chemical reactions. The successful conversion process relies on a decrease in the reduction rate of the metallic precursor to initiate dissolution of Ag in the first stage (a galvanic replacement reaction), then a subsequent backfilling of Au into the hollowed-out structures. Cetyltrimethylammonium bromide (CTAB) surfactant, a key parameter, interacts with metal salt precursor to form a complex species that retards metal reduction. In addition, we demonstrate conversion of solid nano-Ag to solid nano-Pd as well as of Cu foil (10 µm thick) to shiny Au foil.

Au nanorod design as light-absorber in the first and second biological near-infrared windows for in vivo photothermal therapy.

Photothermal cancer therapy using near-infrared (NIR) laser radiation is an emerging treatment. In the NIR region, two biological transparency windows are located in 650-950 nm (first NIR window) and 1000-1350 nm (second NIR window) with optimal tissue transmission obtained from low scattering and energy absorption, thus providing maximum radiation penetration through tissue and minimizing autofluorescence. To date, intensive effort has resulted in the generation of various methods that can be used to shift the absorbance of nanomaterials to the 650-950 nm NIR regions for studying photoinduced therapy. However, NIR light absorbers smaller than 100 nm in the second NIR region have been scant. We report that a Au nanorod (NR) can be designed with a rod-in-shell (rattle-like) structure smaller than 100 nm that is tailored to be responsive to the first and second NIR windows, in which we can perform hyperthermia-based therapy. In vitro performance clearly displays high efficacy in the NIR photothermal destruction of cancer cells, showing large cell-damaged area beyond the laser-irradiated area. This marked phenomenon has made the rod-in-shell structure a promising hyperthermia agent for the in vivo photothermal ablation of solid tumors when activated using a continuous-wave 808 m (first NIR window) or a 1064 nm (second NIR window) diode laser. We tailored the UV-vis-NIR spectrum of the rod-in-shell structure by changing the gap distance between the Au NR core and the AuAg nanoshell, to evaluate the therapeutic effect of using a 1064 nm diode laser. Regarding the first NIR window with the use of an 808 nm diode laser, rod-in-shell particles exhibit a more effective anticancer efficacy in the laser ablation of solid tumors compared to Au NRs.

Scintigraphic assessment of salivary function after intensity-modulated radiotherapy for head and neck cancer: correlations with parotid dose and quality of life.

OBJECTIVE: We investigated salivary function using quantitative scintigraphy and sought to identify functional correlations between parotid dose and quality of life (QoL) for head and neck cancer (HNC) patients receiving intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: Between August, 2007 and June, 2008, 31 patients treated IMRT for HNC were enrolled in this prospective study. Salivary excretion function (SEF) was previously measured by salivary scintigraphy at annual intervals for 2 years after IMRT. A dose-volume histogram of each parotid gland was calculated, and the normal tissue complication probability (NTCP) was used to determine the tolerance dose. QoL was longitudinally assessed by the EORTC QLQ-C30 and H&N35 questionnaires prior to RT, and at one, three, 12 and 24 months after RT. RESULTS: A significant correlation was found between the reduction of SEF and the mean parotid dose measured at 1 year (correlation coefficient, R(2)=0.651) and 2 years (R(2)=0.310) after IMRT (p<0.001). The TD(50) of the parotid gland at 1 year after IMRT is 43.6 Gy, comparable to results from western countries. We further found that contralateral parotid and submandibular gland function preservation was correlated with reduced sticky saliva and a better QoL compared to the functional preservation of both parotid glands, as determined by the EORTC QLQ-H&N35 questionnaire. CONCLUSION: A significant correlation was found between the reduction of SEF and the mean parotid dose. Preservation of contralateral parotid and submandibular gland function predicts a better QoL compared to preservation of the function of both parotid glands.

Automatic computer-aided sacroiliac joint index analysis for bone scintigraphy.

Bone scintigraphy helps to detect sacroiliitis before the radiographic changes. Nuclear medicine physicians interpret lesion on sacroiliac joint by the aid of sacroiliac joint-to-sacrum uptake ratios (sacroiliac joint index, SII). Usually, the SII is measured by manually drawing regions of interest (ROI) over the sacroiliac joints and sacrum, which is a tedious, time consuming, and highly operator dependent procedure. In this approach, we developed an automatic SII measurement program based on fuzzy sets histogram thresholding, anatomy-based image segmentation method and pelvis reference points located by morphological operations. To validate the program, the results of automatic SII measurement from 33 patients were compared with the results of manual SII measurement. For each patient, six SIIs representing the upper, middle, and low portions of the right and left SIIs were obtained. Totally, 198 SIIs were included for linear regression, bias, and precision analyses. The coefficient of determination (R(2)) between our approach and 2 medical experts' manual measurements are 0.923 and 0.917 respectively. The predictive performance (bias, precision) shows a good agreement result. From the result of this study, we expect that this automatic computer-aided approach may be applied to help nuclear medicine physicians in sacroiliitis interpretation.

Surgical outcome of T4a and resected T4b oral cavity cancer.

BACKGROUND: The American Joint Committee on Cancer (AJCC) 2002 staging system (AJCC 2002) suggested that squamous cell carcinoma of the oral cavity (OSCC) with T4b is unresectable. The current retrospective results show that selected T4b patients were resectable with favorable outcomes. METHODS: From January 1996 to December 2000, 103 consecutive untreated T4 OSCC patients (reclassified by AJCC 2002) without carotid artery encasement and skull base extension were eligible for radical treatment. All received head-and-neck magnetic resonance imaging (MRI) and/or computed tomography (CT) scans before operation. The surgical principles were safety margins of > or =1 cm for primary tumors, modified/radical neck dissections for clinical lymph node-positive disease, and supraomohyoid neck dissection for lymph node-negative disease. In all, 95.1% of patients (98 of 103 patients) underwent free-flap reconstructions. Adjuvant radiotherapy or concomitant chemoradiotherapy was administered to those with pathological T4 (AJCC 1997), cervical lymph node metastasis, or close margins (< or =4 mm). Survivals were calculated according to the method of Kaplan and Meier. RESULTS: In all, 58 patients were classified as having T4a disease and 45 were classified as having T4b disease. No statistical difference was observed in the 5-year local control, neck control, disease-free survival, and overall survival rates between the T4a and T4b groups. In multivariate analyses, pathologic lymph node status (pN0-1 vs. pN2) was found to be the sole independent predictor for T4b for local control (P = .012), disease-free survival (P = .005), and overall survival (P = .008). CONCLUSIONS: Selected T4b OSCC patients were found to be resectable with outcomes that were comparable to those of T4a OSCC patients and may benefit from radical surgery, free-flap reconstruction, and adjuvant therapy. A pathologic lymph node status of > or =2 was found to be the sole independent predictor for T4b disease in local control and survival.

Improved diagnostic performance of thallium-201 myocardial perfusion scintigraphy in coronary artery disease: from planar to single photon emission computed tomography imaging.

BACKGROUND: This study was performed to compare Tl-201 myocardial perfusion single photon emission computed tomography (SPECT) with planar scintigraphy in the diagnosis of coronary artery disease (CAD). METHODS: Retrospectively, 240 of 3262 patients, with exercise-redistribution Tl-201 myocardial perfusion scintigraphy performed between January 1990 and October 1997, were analyzed to compare Tl-201 scintigraphy and coronary arteriography. Within 30 days, all 240 patients underwent both coronary arteriography and exercise-redistribution Tl-201 myocardial perfusion scintigraphy with 86 SPECT and 154 planar images acquired. RESULTS: The sensitivities of Tl-201 myocardial perfusion scintigraphy in individual coronary arteries including left anterior descending (LAD) artery, left circumflex (LCX) artery, and right coronary artery (RCA), were 77%/72%, 31%/30%, and 77%/50% in the SPECT/planar study groups, respectively. The sensitivities of CAD detection in patients with single-vessel, double-vessel, and triple-vessel diseases were 96%/82%, 91%/85%, and 96%/90% in the SPECT/planar study groups, respectively. CONCLUSION: SPECT images provide greater advantages over planar images for better detection of the number, location, and extent of CAD. Cardiac SPECT does improve the accurate interpretation in abnormal Tl-201 distributions due to the higher contrast resolution and better separation of overlapping myocardial regions.

Incidental detection of an invasive thymoma during thallium-201 imaging for coronary artery disease.

Thallium-201 (Tl-201) is widely used for myocardial perfusion imaging, but is also reported to have potential tumor-seeking properties. Tl-201 uptake has been described in various malignant diseases, including thymic tumors. Thymomas are the most frequent tumors of the anterior mediastinum, and chest pain is one of the major presentation symptoms. Sometimes, a thymoma may be overlooked on chest plain film. We report on a case of a 63-year-old man who had a history of hypertension and suffered from intermittent chest pain for several weeks. He underwent a Tl-201 stress test to evaluate the presence of coronary artery disease, and during the test, abnormal uptake over focal extracardiac activity in the left upper mediastinum was incidentally revealed. Furthermore, chest computed tomography identified a 6-cm left anterior mediastinal mass. Mediastinal tumor resection was carried out, and the pathological examination demonstrated an invasive epithelial-type thymoma, which had invaded the left innominate vein. Subsequently, the patient received postoperative radiotherapy and thenceforth responded well to treatment. A Tl-201 scan has the potential to play a part in tumor detection and clinical assessment of therapeutic effects.